A Novel Hedgehog Waveguide and its Application in Designing a Phase Shifter Compatible With Hollow Waveguide Technology

A new Hedgehog waveguide, consisting of a bed of nails embedded in a host rectangular hollow waveguide, is proposed and investigated as a promising state-of-the-art low-loss waveguide for millimeter-wave frequency bands. The proposed Hedgehog waveguide gets its name from its electromagnetic behavior. As hedgehogs root through hedges and other undergrowth in search of their favorite food, the proposed waveguide root through its embedded bed of nails. When we choose a host waveguide technology, it is worthwhile spending some time weighing up the pros and cons of the various types of waveguides on offer. The proposed Hedgehog waveguide is extremely low loss and is compatible with the hollow waveguide technology, which gives the ability to develop different components such as low-loss flat phase response phase shifters. In this paper, the proposed Hedgehog waveguide is analytically investigated, and a transition to the hollow waveguide is designed. Moreover, the low-loss nature of the designed Hedgehog waveguide is compared with the ridge gap waveguide, substrate-integrated waveguide (SIW), hollow waveguide, and microstrip line. Finally, the proposed waveguide is designed, simulated, and fabricated. The simulated and measured results show a good agreement, which validates the proposed concept.